Here are three real objects: a ball, a tin and a dice.

If I gave each one a gentle push across the desk, which would roll away and which would just slide and stop? Have a good look before any hands go up.

Watch five solids sorted into their names on the board. Look for the one thing that gives each solid away:

• Cube — flat square faces, like a dice
• Cuboid — a box shape
• Sphere — fully round
• Cylinder — a tin shape
• Cone — comes to a point

Today we sort these pictures together onto the board: a dice, a cereal box, a football, a tin of beans, an ice-cream cone, and then a kitchen-roll tube and a globe. We name each one, then decide which shape-name it belongs under.

Now sort real solids by what they DO, not just their name. On the board, sort the tray into two groups:

• Solids that roll
• Solids that only slide